Campylaimus mirus Gerlach, 1950

Holovachov, Oleksandr, 2019, New and known species of the genus Campylaimus Cobb, 1920 (Nematoda: Araeolaimida: Diplopeltidae) from North European marine habitats, Biodiversity Data Journal 7, pp. 46545-46545 : 46545

Campylaimus mirus Gerlach, 1950

Materials

Type status: Other material. Occurrence: catalogNumber: SMNH-177076 ; individualCount: 1; sex: female; Location: country: Germany; locality: Helgoland ; georeferenceProtocol: label; Identification: identifiedBy: Oleksandr Holovachov; dateIdentified: 2018; Event: year: 2011; month: 5; day: 31; habitat: Sediment

Description

Measurements. Table 4 . Adult. Figs 22 , 23. Cuticle without longitudinal striation. Space between dorsal and ventral limbs of amphid developed. Lateral alae narrow, with crenate margins. It originates at posterior end of ventral limb of amphid and ends in a long expansion along posterior third of tail. Secretory-excretory pore opens posterior to cardia, at level with anterior part of intestine. Tail with clavate terminal part. Male. Not found. Female. Anteriormost edge of amphid positioned anterior to oral opening. Dorsal limb of amphid extends for a short distance posteriorly, equal to 1.7 labial region diameters in length. Ventral limb of amphid extends along pharyngeal region to level of anterior third of the pharynx; 1.4 times the length of dorsal limb. Ventral limb of amphid 1.3 wider than dorsal limb. Interamphideal space very broad, extends along pharyngeal region to same level as ventral limb. Vagina straight. Spermatheca absent, spermathozoa in uterus. One pair of ventrosublateral setae located along middle of tail and one pair of dorsosublateral setae located half way between posterior end of lateral alae and tal terminus.

Diagnosis

Body 0.93 mm long; cuticle without longitudinal striation; anteriormost edge of amphid anterior to oral opening; dorsal limb of amphid equal to 1.7 labial region diameters in female; ventral limb of amphid extends towards anterior part of pharynx, 1.4 times the length of dorsal limb in female; ventral limb of amphid is 1.3 wider than dorsal limb; interamphideal space extends to same level as ventral limb; secretory-excretory pore opens posterior to cardia; tail equal to 7.3 anal body diameters in length, with clavate terminal part.

Taxon discussion

Original description of this species is based on a single male specimen ( Gerlach 1950), while the recent specimen is a female. Both specimens are similar in most body measurements and in the morphology of the anterior end: position of the oral opening posterior to the anteriormost edge of the amphid and in the shape of the amphid with developed interamphideal space, ventral limb of the amphid 1.4 times the length of the dorsal limb and extending to the level of the anterior third of the pharynx. Observed differences between the two specimens include slender body (a = 42) shorter amphid (36 µm) and broader annules (5 µm) in the male (vs. a = 28, 46 µm and 2 µm, respectively, in the female).

Figures

Figure 22. Campylaimus mirus Gerlach, 1950 (a-b) and Campylaimus longispiculus sp. n. (c-d) (scale bars = 20 µm, PIJ = pharyngo-intestinal junction / cardia, EP = secretory-excretory pore): a: female pharyngeal region; b: female tail; c: male pharyngeal region; d: male caudal region.